Compressor system



Dec. 23, 1930. L. WILSON COMPRESSOR SYSTEM Original Filed Oct. 12, 1927 2 Sheets-Sheet l .Zhevemiar: 0 [eozacard iz/zaam 9 4.; A- m4- Dec. 23, 1930. w o 1,786,278

COMPRESSOR SYSTEM Original Filed Oct. 12, 1927 2 Sheets-Sheet 2 H II ' Ina/622%:-

' ,leona/rd Mailman. b M 4- MM- Patented Dec. 2 3, 1930 UNITED STATES PATENT OFFICE LEONARD WILSON, OF SALT LAKE CITY, UTAH, AISIGIOB TO SULLIVAN MACHINERY COMPANY, A CORPORATION OF MASSACHUSETTS COMPRESSOR SYSTEM Application filed October 12, 1927, Serial No. 225,789. Renewed February 27, 1830.

My invention relates to' automatic means for controlling loading and unloading of air or gas com ressors.

It has or an object to provide an im- 5 proved arrangement for controlling loading automatically controlling loading and unloading in response tothe speed of the comressor in combination with means automatically responsive to receiver tank pressure for controlling loading and unloading while the compressor is running at normal speed. A still further object is to rovide means for unloading both cylinders oi a compound compressor until the compressor has come up to speed and other means acting through said unloading means to control loading and unloading of the low' pressure cylinder in response to variations of pressure in the receiver tank while the compressor is running at normal s eed. Other objects and advantages will, however, hereinafter more fully appear.

In the accompanying drawings I have shown for purposes of illustration one form which my invention may assume in practice.

In these drawings,-

Fig. 1 is a diagrammatic view of a compound compressor and an unloading'system associated therewith.

Fig. 2 is a front elevation of a compound compressor and its driving motor, parts being shown in section to facilitate illustration and with the intake unloader in closed position.

Fig. 3 is a fragmentary sectional view of the unloading mechanism for the high pressure cylinder.

Fig. 4 is a vertical section on line 4-4 of Fi 3.

Figs. 5 and 6 are detail sectional views of the solenoid operated valves illustrated in Fig. 1.

Fig. 7 is a detail sectional view of the special, check valve which I employ in connection with myunloading system.

In the illustrative embodiment of my invention there is shown an angle com ound com ressor having a low pressure cy inder 1, a igh pressure cylinder 2, and an intercooler 3 interposed between the two cylinders. The compressor is shown as being connected to a synchronous motor 4 having field collector rings 5 supplied with current from an exciter 6 which 15 driven by the synchronous motor. An oil pump 7 is driven from the compressor crank shaft 8 by any suitable means such as a link 9; and this pump is adapted to supply oil under pressure from the hollow crank case 10 to the standpipe 11 and reservoir 12 as well as to the unloader system in a manner which will be later described. The overfiow from the reservoir 12 is conducted through a central pipe back to the crank case at 13 (see patent to Wine-.

man, 1,602,791).

As best shown in Fig. 2, the intake unloader valve 14 is adapted to be raised to open or loaded position by means of pistons 15 reciprocatin in cylinders 16 and connected to each otheriy means of a crosshead 17. These pistons are adapted to be automatically raised y oil ressure from the oil pump 7 flowing through the pipe 18, valve 19, p1 e 20, an then into the cylinders 16 throug the pipe 21. The assage 22 in the walls of one of the cylin ers 16 serves to conduct any oil which may leak past the pistons 15 to the crank case by way of a pi e 23. The oil in cylinders 16 may be drained back to the crank case through a valve 24 and pipe 25 to allow the intake valve 14 to drop and unload the compressor.

The means for unloading the high pressure cylinder will now be briefly described. A diaphragm 26 is mounted in a casing 27 and supported by a. bracket 28 on the compressor. One side, herein called the pump side, of the diaphragm is connected by an oil line 29 to a T 30 inserted in the oil line 18 leading from the oil pump. The diaphragm is adapted to actuate a lever 31 pivoted at 32 to a link 34. The lever 31 in turn actuates a member 35 to which it is pivoted at 36. This member can ries a yoke 37 as best shown in Fig. 4, which yoke surrounds the lower valve 38 connected to the lower end of the hi h pressure cylinder. A plunger 39 secured in t is yoke is so mounted as to engage the ball valve 40 and unseat the same when pressure on the diaphragm is relieved and the lever 31 is operated by the spring 41. A valve 42 is connected to the upper end of the high pressure cylinder and this valve is identical in construction with the valve at the lower end of the cylinder and is adapted to be simultaneously actuated through the lever 31 by means of rod 43 secured in the upper end of the yoke 37.

In accordance with my invention I haveprovided means for loading and unloading the compressor automatically as the ressure in the receiver tank varies. For t is purose I utilize a pressure operated switch generally designated 44, which is adapted to open a circuit between the contacts 45 when the pressure on the diaphragm 46 reaches a predetermined maximum. A spring 47 operating on a bell crank lever 48 closes the switch when the pressure in the receiver goes down. For operating the valves 19 and 24 to effect loading or unloading of the compressor accordingly as the pressure switch 44 closes or opens, there are provided the solenoids 50 and 51 respectively arranged to operate the valves 24 and 19. Any suitable source of current may be utilized for supplying power to the solenoids when the pressure switch is closed and is herein shown as being the generator 5 which supplies exciting curent to the motor. As will be noted, the two solenoids are connected in 1parallel with each other, though of course t ey may also be connected in series. These valves are illustrated in section in Figs. 5 and 6, Fig. 5 showing the valve 19 and Fig. 6 showing the valve 24 in the positions they occupy when the solenoids are energized. The valve 19 has a port 52 which is adapted to establish communication between the pipes 18 and 20 when the solenoid 51 is energized. In the valve 24 is a similar port 53 which is adapted to open communication betwen the pipes 21 and 25 when its controlling solenoid is de-energized. For the purpose of allowing the pump to build up suflicient pressure in the lines 18 and 29 to operate the unloading system, I have interposed a special check valve 54 in the line leading to the oil reservoir. This check valve has a spring controlled valve element 55 which is held in substantially closed position by the spring 56 until suificient pressure builds up on its lower side to raise it. The pump and check valve are so designed that sufiicient pressure for operating the unloaders will not be generated until the motor has reached substantially its normal operating or synchronous speed.

Although it is believed the operation of the therefore the solenoids 50 and 51 and not I energized though by reason of low discharge line pressure the switch 45 is closed. Accordingly the valve 19 is closed and the valve 24 is in open position. The lower ends of the cylinders 16 therefore communicate with the sump and are disconnected from the oil pump discharge.

Now, let it be assumed that the motor 4 is started. The generator 6 builds up its voltage quickly and the solenoids 51 and 50 shift the valves 19 and 24 to the positions shown in Fig. 6 substantially before the motor 4 reaches full speed. The oil pump starts with the first turning over of the unloaded com pressor, but the quantity discharged would not sufiice, until the motor 4 is up to speed and synchronized to raise the pistons 15 and diaphragm 26. When however these are raised the intake valve 14 is opened and the valves 38, 42 closed and loading is complete.

As lon as the pressure in the discharge line remains below the maximum desired the pressure switch 45 remains closed. If the pressure is exceeded, diaphragm 46 moves lever 44 so that the circuit through the solenoids 50, 51 is opened by switch 45, and the valves 19 and 24 are moved to cut oil cylinders 16 from the pump and vent them to the sump, thus unloading the low pressure cylinder.

It will of course be understood that it is not necessary to operate the unloader valves 38 and 42 for the high pressure cylinder except at starting. The valves for controlling the flow of oil are used only in the line leading to the low pressure cylinder unloader; and during the time that the motor 4 is running, variations in receiver tank sure control loading and unloading o the low pressure cylinder. Due to leakage past the intake closure valve of the low pressure cylinder, it may be desirable to provide, in addition, an automatic unloading means of the type disclosed in the patent to H. C. J ohansen, No. 1,496,543, June 3, 1924, which is operative to permit the automatic discharge, when the compressor is completely unloaded, of any small leakage past the intake closure valve directly to the atmosphere from the high pressure cylinder. The operation of such high pressure unloader valves is fully disclosed in the patent and it is not necessar to describe it herein.

s a result of my invention it will be obviresous that I have devised an improved arrangement for insuring that the compressor will be completely unloaded during the time the motor is being started and coming up to speed, and have combined therewith a simple arrangement for effecting control of unloading in response to variations in the receiver tank pressure.

While I have in this application specifically described one form whic my invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the inventlon' maiy be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

WVhat I claim as new and desire to secure by Letters Patent is:

1. In combination, a pump having a cylinder, means operable by ressure variations for loading said pump cy inder, means other than said 0 linder for producing pressure variations or effecting operation of said loading means, and means responsive to pressure variations produced by operation of said pump for controlling the operation of said loading means by the first mentioned pressure variations to effect loading and unloading in response to said second mentioned pressure variations during continuous running of said pump.

2. In combination, a pump, a valve whose position determines whether said pump be loaded or unloaded, actuating means for said valve operable by unbalanced pressure, means driven with the compressor for creating an unbalanced pressure on said actuating means, and means governed by pressure variations produced by loaded operation of said pump and operatlve during continued running of the latter, for controlling the unbalanced pressure and thereby the loading of said pump.

3. In combination, a pump, unloading means therefor, operating means for said unloading means including a second pump driven with said first mentioned pump, and means controlled by pressure conditions produced by operation of said first mentioned pump for controlling operation of said unloading means by the second mentioned pump, for effecting loading and unloading of said first mentioned pump while the latter is driven continuously.

4. In combination, a pump, a synchronous driving motor therefor having an exciter, pressure fluid operated mechanism for controlling loading and unloading'of said amp, and pump discharge pressure controlle electrically operated controlling means for said mechanism supplied with current from said 'cxciter.

5. In combination, a pump, a synchronous driving motor therefor havin" an exciter driven by the synchronous mo or, pressure fluid operated mechanism for controllin loading and unloading of said pump, an pump discharge pressure controlled, electricall loa ing and unloading mechanism for which said exciter constitutes the source of current supply.

6. In combination, a pump operable to vary a pressure, a synchronous driving motor therefor having and driving its own exciter, pressure fluid operated mechanism for controlling the loading and unloading of said pump, and electrically operated controlling means for said mechanism including a circuit for which said exciter constitutes the source of current supply and a switch controlling said circuit and having actuating means governedby the pressure which said pump is operable to vary.

7. In combination, a compressor, a synchronous motor for driving the same, unloading means for said compressor, and electromagnetic means t'or controlling said unloading means, said electro-magnetic means having a controlling circuit in parallel with the field of said motor.

8. In combination, a compressor, a synchronous motor for driving the same, unloading means for said compressor, electro-magnetic means for controlling said unloading means, said electro-magnetic means having a controlling circuit in parallel with the field of said motor, and means for opening and closing said circuit in response to variations of pressure produced by loaded operation of said compressor.

a 9. In combination. a compressor, a synchronous motor for driving the same, unloading means for said compressor, and electromagnetic means for controllin said unloading means, said electro-magnetic means having a controlling circuit in parallel with the field of said motor and provided with a switch opened to unload the compressor when the compressor discharge pressure reaches a predetermined maximum.

10. In combination, a pump, a driving motor therefor, and unloading means for said a pump including a movable element whose position determines whether or not the pump is loaded or unloaded and means for controlling the position of said element including a plurality of controls each dependent on the speed of said pump and both adapted to control movement of said element.

11. In combination, a pum a driving motor therefor, and pressure uid operated means for controlling loading of said pump including a source of pressure fluid supply inadequate to effect loading until said pump comes up to s cod and controllin means for the pressure uid supplied inclu ing an electrical control system de-energized' when said pump is idle.

12. In combination with a compressor cyloperated controlling means for said inder, pressure fluid actuated means for loading said compressor cylinder, means other than said cylinder responsive to the speed of said compressor for supplying pressure fluid to said loading means, and means responsive to variations in compressor discharge pressure for controlling said pressure fluid supplying means to eflect loading and unloading in response to variations in compressor discharge pressure during continuous running of said compressor.

13. In combination with a compressor, pressure fluid actuated means for loading said compressor, a pump driven in accordance with the speed of the compressor for generating fluid pressure for said loading means, the pressure supplied to said loading means at the normal running speed of the compressor being required for effecting loading of the compressor by said loading means, and means for controlling the sup ly of pressure fluid for loading and unloa ing said compressor in response to variations in the discharge pressure of said compressor during continuous running of the compressor at its normal speed.

14. In combination with a compressor, means under a dual control for controlling loading of said compressor including means responsive to the speed of said compressor for controlling loading, and a second means for controlling loading and unloading during continuous running of the compressor, said second controlling means being responsive to compressor discharge pressure and being operative to load the compressor only when said first mentioned controlling means is in condition to permit loading of the compressor.

15. In combination, a compressor, an unloader for the compressor, unloader actuating means for moving said unloader to loaded position when subjected to suflicient pressure, a pump driven in accordance with the speed of the compressor for generating hydraulic pressure for said actuating means, said hydraulic pressure varying with the speed of the pump and being suflicient to operate the unloader to loaded position only at or near the normal running speed of the COlll pressor. and means for controlling loading and unloading in response to variations in discharge pressure of the compressor while running continuously at its normal speed including means for controlling the flow of liquid to and from said hydraulic actuating means.

16. In combination, loader for the compressor, pressure fluid actuated means for controlling said unloader, a pump driven in accordance with the speed of the compressor for generating fluid pressure for said pressure fluid actuated controlling means, means for discharging a portion of the pressure fluid to prevent generation a compressor, an un-' of sufiicient pressure to operate said pressure fluid actuated controlling means to effect loading until said compressor has reached substantially its normal running speed, and means for controlling the supply of fluid pressure to said pressure fluid actuated controlling means to govern loading and unloading of said compressor in response to variations in compressor discharge pressure while the compressor operates continuously at its normal running speed.

17. In combination, a compressor, an unloader for the compressor, pressure fluid aetuated means for controlling said unloader, a pump driven in accordance with the speed of the compressor for circulating oil to lubricate a portion of said compressor and to supply pressure fluid to actuate said controlling means, the pressure supplied to said controlling means at the normal running speed of the compressor being required for operating said controlling means, and means for controlling flow of oil to said controlling means to cause loading and unloading of the compressor in response to variations in compressor discharge pressure during continuous running of said compressor.

18. In combination with a compressor, means movable into different ositions to effect loading and unloading 0 said compressor, pressure fluid actuated means for eifecting movement to one of said positions, means for supplying fluid under varying pressure to said pressure fluid actuated means, the pressure under which the fluid is supplied varying in accordance with the speed of the compressor, and means responsive to variations in compressor discharge pressure for controlling the supply of pressure fluid to said pressure fluid actuated means, said controlling means including electrically operated means.

19. In combination with a compressor, means movable into different positions to effect loading and unloading of said compressor, pressure fluid actuated means for efi'ectin g movement to one of said positions, means for su plying fluid under varying pressure to sai pressure fluid actuated means, the pressure under which the fluid is supplied varying in accordance with the speed of the compressor, and means responsive to variations in compressor discharge pressure for controlling the supply of pressure fluid to said pressure fluid actuated means, said controlling means comprising a valve for controlling flow of fluid to said pressure fluid actuated means, and means responsive to variations in compressor discharge pressure for c'pntrolling the operation of said valve while the compressor is running continuously.

20. In combination with a compressor,

means movable into difierent positions to effect loading and unloadin of said compressor, pressure fluid actuate means for efi'ect pressure ing movement to one of said positions, means for supplying fluid under varying pressure to said pressure fluid actuated means, the pressure under which the fluid is supplied varying in accordance with the" speed of the compressor, and means responsive to variations in com ressor discharge pressure for controlling t e supply of,pressure fluidto said pressure fluid actuated means, said controlling means comprising valve means for controlling flow of fluid to said pressure fluid actuated means, electro-magnetic means for operating said valve means, and a pressure switch governed by compressor discharge pressure for opening and closing the circuit through said electro-magnetic means.

21. In combination with a compressor, means movable into diflerent positions to effect loading and unloading of said compressor, a receiver, pressure fluid actuated means for effecting movement to one of said positions, a pump driven in accordance with the speed of the compressor for generating flu d pressure for operating said pressure fluid actuated means, restricted means for bypassing fluid from the pump to prevent building up of fluid pressure acting on said pressure fluid actuated means suflicient to operate the same until said compressor has reached substantially its normal running speed, and means responsive to variations in receiver pressure for controlling the fluid pressure acting on said pressure fluid actuated means during continuous running of the compressor, said controlling means comprising a valve for controlling flow of fluid to said unloading means, and means governed by variations in receiver pressure for'controlling operation of said valve.

22. In combination with a compressor, means movable into different positions to effect loading and unloading of said compressor, a receiver, means actuated by hydraulic for eiiecting movement to one of said positions, a pump driven in accordance with the speed of the compressor for circulating oil to lubricate a portion of the compressor and to generate pressure to operate said pressure fluid actuated fneans, restricted means for bypassing fluid from the pump to prevent building up of fluid pressure acting on said pressure fluid actuated means sufficient to operate the same until said compressor has reached substantially its normal running speed, and means responsive to variations in receiver pressure for controlling the hydraulic pressure acting on said pressure fluid actuated means, said controlling means comprising valve means in the oil line leading from said pump to said pressure fluid actuated means, electro-magnetic means for operating said valve means and a pressure switch governed by variations in receiver pressure for opening and closing the circuit through said electro-magnetic means.

23. In combination with a compressor, means movable into difl'erent positions to effect loading and unloading of said com-.

pressor, a receiver, means actuated by hydraulic pressure for efl'ecting movement to one of said positions, a pump driven in accordance with the speed of the compressor for circulating oil to lubricate a portion of the compressor and to generate pressure to operate said pressure fluid actuated means, restricted means for bypassing the fluid from the pump to prevent building u of fluid pressure acting on said pressure uid actuated means sufficient to operate the same until said compressor has reached substantially its normal running speed, means responsive to variations in receiver pressure for controlling the hydraulic pressure acting on said pressure fluid actuated means, said controlling means comprisin valve means in the oil line leading from sai pump to said pressure fluid actuated means, electro-magnetic means for operating said valve means, a pressure switch governed by variations in receiver pressure for opening and closing the circuit through said electro-magnetic means, and a synchronous motor for driving the compressor having an exciter driven thereby, said electro-magnetic meansbeing supplied with current from said exciter.

24. In combination, a compressor, an unloader for the compressor, means other than the compressor but dependent upon running of the compressor for generating power medium to operate said unloader to loaded position when supplied thereto, and means for controlling flow of said power medium to said unloader to control loading and unloading automatically in response to compressor discharge pressure while the compressor is running continuously, including a controlling device responsive to compressor discharge pressure. 7

25. In combination, a compressor, an unloader for the compressor, means other than the compressor dependent on running of the compressor above a predetermined speed for generating power medium to operate said unloader to loaded position when supplied thereto, and means for controlling flow of said power medium to said unloader to control loading and unloading automatically in response to compressor discharge pressure while the compressor is running continuous- 1y, includin a control device responsive to compressor discharge pressure.

26. In combination, a compound compressor having a high and a low'pressure cylinder, an unloader for the low pressure cylin- (ler, an unloader for the high pressure cylinder, means other than the compressor dependent upon running of the compressor above a predetermined speed for generating power medium to operate said unloaders to loaded position when supplied thereto, said unloaders being normally'in unloaded position, and means for controlling flow of said power medium to one of said unloaders to control loading and unloading automatically in response to compressor discharge pressure while the compressor is running continuousl at normal speed, including a controlling gevice responsive to compressor discharge pressure.

27. In combination, a compressor, a motor for driving the compressor, a reservoir containing liquid, an unloader for the compressor, means actuated by hydraulic pressure controlling the unloader and connectible with said reservoir, 9. liquid pump driven by power from said motor in accordance with the speed of the compressor for generating pressure for said hydraulic actuating-means, said pump having its intake connected to said reservoir, restricted bypass means associated with said pump for preventing said pump from generating sufliclent pressure to cause operation of the unloader to load the compressor until the compressor is up to normal operating speed, and means for controllin said'hydrau'lic actuating means to cause loa ing and unloading of the compressor in response to compressor discharge pressure variations during continuous running of the compressor includin valve means operable to close connection Fetween said pump and said unloader controlling means and to permit flow from said unloader controlling means to said reservoir.

In testimony whereof I afiix my signature.

LEONARD WILSON.

unloaders being normally in unloaded position, and means for controlling flow of sald power medium to one of said unloaders to control loading and unloading automatically in response to compressor discharge pressure while the compressor is running continuously at normal speed, including a controlling device responsive to compressor discharge pressure.

27. In combination, a compressor, a motor for driving the compressor, a reservoir containing liquid, an unloader for the compressor, means actuated by hydraulic pressure controlling the unloader and connectible with said reservoir, a liquid pump driven by power from said motor in accordance with the speed of the compressor for generating pressure for said hydraulic actuating-means, said pump having its intake connected to said reservoir, restricted bypass means associated with said pump for preventing said pump from generating suflicient pressure to cause operation of the unloader to load the compressor until the compressor is up to normal operating speed, and means for controlling said hydraulic actuating means to cause loading and unloading of the compressor in response to compressor discharge pressure variations during continuous running of the compressor including valve means operable to close connection between said pump and said unloader controlling means and to permit flow from said unloader controlling means to said reservoir.

In testimony whereof I afiix my signature.

LEONARD WILSON.

CERTIFICATE OF CORRECTION.

Patent No. l, 786, 278.

Granted December 23, 1930. to

LEONARl) WILSON.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: the word "provide" insert the words an improved system including; page 2, line 36, for the numeral "5" read 6, and for the misspe led Word "curent" read current, and line 77, for the word "and" second occurrence, read are; page 5, line 37, claim 21, for the word "unloading" read pressure fluid actuated; and that the said Letters Patent should be read with these corrections therein that the same mi? c'b't'i'f orm to the record of the case in the Patent Office.

Signed and sealed this 24th day of March, A. D. 1931.

(Seal) M. 1.} Moore.

Acting Commissioner of Patents.

Page 1, line 21, after CERTIFICATE OF CORRECTION.

Patent No. 1,786, 278. Granted December 23, l930, to

LEONARD WILSON.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1. line 21, after the word "provide" insert the words an improved system including; page 2, line 36, for the numeral "5" read 6, and for the misspelled word "curent" read current, and line 77, for the word "and" second occurrence, read are; page 5, line 37, claim 21, for the word "unloading" read pressure fluid actuated; and that the said Letters Patent should be read with these corrections therein that the same may 'contorm to the record of the case in the Patent Office.

Signed and sealed this 24th day of March, A. D. 1931.

M. Jn- Moore, (Seal) Acting Commissioner of Patents. 

